HAN, HAN derivatives and hydroxylamine are useful oxidizers in various propellant formulations such as, for example, those used for guns, rockets, satellites, gas generators, and the like. HAN, specifically, is an oxidizer for propellants that has recently become available in commercial quantities. Processes for preparing HAN are set forth in U.S. Pat. Nos. 5,510,097 and 5,258,104. HAN, its derivatives and hydroxylamine have many desirable properties, such as high oxygen content, high water solubility as well as containing no halogen atoms. Unfortunately, the storage stability for HAN, HAN derivatives or hydroxylamine, and compositions containing them has been, and continues to be, a concern for which solutions are sought. The need exists to enhance the storage stability of HAN, HAN derivatives or hydroxylamine and compositions containing them.
Certain stabilizers for HAN, HAN derivatives and hydroxylamine are known. Some have been used to protect compositions containing HAN, HAN derivatives and hydroxylamine from unwanted degradation during storage prior to use. As disclosed in U.S. Pat. No. 3,145,082, chelating agents, such as the tetrasodium salt of ethylenediaminetetraacetic acid (EDTA) have been used as stabilizers for hydroxylamine. The prior art further teaches the use of aminophosphonic acids as stabilizers for HAN-based liquid propellant (LP) compositions. This is set forth in a technical report by R. Hansen et al., entitled "Processes for Assessing the Thermal Stability of HAN-Based Liquid Propellants, Final Report," BRL-CR-635, Ballistic Research Laboratory, Aberdeen Proving Ground, Md. (Jul., 1990).
There exists a continuing need to develop and provide means for which to provide enhanced stability to HAN, HAN derivatives and hydroxylamine, as well as for compositions comprising these. Being able to accomplish this in a cost-effective fashion is further desirable. The present invention provides a solution to meet the needs described.